A Dosimetric Device Based on a CMOS Image Sensor for Interventional Radiology
In evidenza

The RAPID (Real Time Active Pixel Dosimetry) project is focused on radiation protection in Interventional Radiology. During all their professional activities, interventional radiologists and staff members are frequently exposed to protracted and fractionated low doses of ionizing radiation. In order to comply with international guidelines on radiation protection, exposure to ionizing radiation also restricts the number of procedures that operators can periodically undertake. It is therefore necessary to minimize individual exposure to X-rays during radiological procedures through an on line monitoring of absorbed dose.

Certified dose monitoring of operators is performed using passive dosimeters (e.g. ThermoLuminescence Dosimeters, TLD) but their major drawback is that they do not provide a real-time measurement. Active devices that perform a real-time measurement (Active Personal Dosimeters, APD), based on semiconductor, are already commercially available; due to the specificity of the X-ray fields used in Interventional Radiology/cardiology (low energies and pulsed fields), though, the current technology of Active Personal Dosimeters (APD) can be inadequate.

In such a context, we proposed portable instrumentation capable of measuring measure accumulated dose in real-time, in order to pursue the following: i) drive online the staff operation, with the possibility of dose reduction providing an alarm; ii) collect offline the results of dose measurements with the aim to obtain a temporal profile of the absorbed dose correlated with the specific activities of the staff during the procedure. In this way, it is possible to plan the number and type of procedures that interventionists can undertake.

The block diagram of the proposed architecture includes the following (see Figure): a sensor featuring an Active Pixel Sensor (APS) architecture; a digital signal processing unit to assess dose information from sensor data; a control unit; a wireless interface to transmit data and collect them in a remote workspace; a graphical user interface to manage collected data.